1. Field of the Invention
This invention relates to a unidirectionally visible (or image-visible) printing member which brings about optical effects different from each other on both sides. More particularly, it relates to a unidirectionally visible printing member in which any images such as characters and figures printed on the surface are visible from the outside, but are invisible from the inside through which the exterior can be seen, which is usable for decoration, advertisement and so forth.
2. Related Background Art
Sheets so designed that any images such as characters and figures printed thereon are visible from the outside when attached to, e.g., windowpanes of automobiles or shops but the images are invisible and the outside view can be seen through attract attention as new advertisement mediums. For example, as shown in FIG. 1A, a sheet having a dark-color layer 103 on its one side and an image 104 formed on its opposite side is provided with a large number of minute holes 105 and then, after a release sheet 101 has been peeled off, is attached to, e.g., glass 106 with an adhesive provided on the dark-color side (FIG. 1B) as known in the art. Also proposed is a method in which a base pattern having a black or dark-color stripe or small-hole pattern is provided on a transparent film and images are printed so as to cover the base pattern completely.
These methods, however, have problems such that very strict registration (positional adjustment) must be made at the time of printing, or an order must be given to printing traders because a means such as gravure printing or offset printing is used resulting in a large printing lot and taking considerable time and cost for preparation.
In instances where the sheets are attached to windowpanes of automobiles or shops as advertisement mediums, the image surfaces must face the outside of a car or the outdoors. Conventional sheets, however, are processed to make them adhesive (adhesive-processed) on the dark-color side, and hence must necessarily be attached to the outside of the windowpane. Hence, there has been a problem that the sheets attached onto windowpanes may be affected by, e.g., rainfall or car washing to tend to cause a deterioration due to water or detergents to become damaged. In order to prevent such a deterioration, it is possible to apply a cover film over the whole area of the surface on which images have been formed. This, however, complicates steps and also requires a cost, and hence is not practical.
On the one hand, in order to attach the sheet to the windowpane on its inside, the sheet must be adhesive-processed on the side of printed images. It, however, is difficult to print images on the surface having been adhesive-processed. It has also been difficult in view of steps to apply pressure-sensitive adhesive on the printed images.
The present invention was made in order to solve such problems. Accordingly, an object of the present invention is to provide a unidirectionally visible printing member which has simple construction and can be prepared at a low cost, and which can be handled so simply that even ordinary consumers can readily print images thereon by means of commercially available printers and attach it as a printed member to a windowpane and the like.
Another object of the present invention is to provide a unidirectionally visible printing member with which image-formed sheets can be attached to glass on the inside of automobiles, shops and so forth, having hitherto been difficult, and may hardly be affected by outdoor conditions.
The unidirectionally visible printing member of the present invention comprises a light-transmitting base material, a pressure-sensitive adhesive layer comprised of a re-releasable pressure-sensitive adhesive, formed on the base material, and a sheet member having an opaque layer and an image-forming layer and having through-cuts which pass through the image-forming layer and the opaque layer, formed on the pressure-sensitive adhesive layer; the sheet member, when peeled, being capable of remaining partly on the pressure-sensitive adhesive layer in conformity with the cuts, and the pressure-sensitive adhesive layer being capable of remaining on the base material and being uncovered at the part other than the part where the sheet member remains on the pressure-sensitive adhesive layer.